Getting Started

[cityy]

Welcome to the official Quake Live mapper's corner where everything turns around creating your own custom levels. Just like everything else in live, making maps requires a bit of patience in the beginning but almost goes by itself once you have gotten comfortable with it.
To make getting started as easy for you as possible this thread shall gather resources related to anything you should know for making your own maps.

Video Tutorials

01 Setting up your Quake Live mapping environment
02 Navigating in GTKradiant 1.6.3
03 Making your first room in Radiant
04 Connecting two rooms, Jumppads, Teleporters
05 Creating A Simple Door
06 Creating Liquid Volumes (Water, Lava)
07 Two-Point Clipping (Angled Corners)
08 Grid Size, Edge- And Vertex Editing
09 Curved Surfaces

TO BE CONTINUED.

Text Based Tutorials

GTKradiant 1.6.3 is still a very young version of GTKradiant so there aren't any tutorials working with it besides the video tutorials linked above. However, tutorials using version 1.4 and Quake III translate almost 100% to 1.6.3 so you can read and utilize those without any concerns.

- Worldspawn Archive tutorial
- Bubba's GTKradiant tutorial mirrored by Delirium
- Tutorials by Victor Karp (GERMAN)

QuakeNet IRC

If you are getting stuck, feel free to join the official GTKradiant channel on QuakeNet IRC and ask more experienced map makers for help. (Note that this channel is not QL exclusive so there are people from other mapping communities hanging out there as well)

[*B4ZE]

http://q3a.ath.cx/level_design/ this link seems to not work.

[cityy]

Yes, the worldspawn archive tutorial recently moved over to: http://ws.q3df.org/level_design/
Sorry and thanks for pointing it out!

[Theftbot]

ALSO:
Q3W LEM

[AgentofDarkness]

Pretty good start tutorial, very complicated program though

[Obsidian]

Official GtkRadiant end-user site
GtkRadiant Manual (kind of old but still one of the best resources for beginners)
Official Q3Map2 site
Q3Map2 Shader Manual

[cityy]

Pretty good start tutorial, very complicated program though

It might seem complex for you at the beginning but take your time and soon you will be able to easily handle it.
Feel free to ask any questions.

@Obsidian:
Thank you, I'll look to get those links added to the OP.
Not sure what's up with icculus.org - most likely just temporary issues.

[*B4ZE]

@Obsidian : looks like 2 of the links you gave are not working, http://www.icculus.org/ seems to not work.

[Phaneuf]

I had a question for cityy. Is it possible to make an item in quake mobile? for instance a moving platform would the item stay stationary or would it move with the platform?

[cityy]

You can not make weapons (or items in general) move unfortunately. All you can do is have it float in the air like MH on The Longest Yard for example.